Tag URLs
I think it would be good if the user had the ability to link URLs to tags, I.E., you have a creator tag like creator:muffin let's say muffin posts in multiple places I think it would be useful to link their pages to the creator tag, which could also tag the corresponding posts if the user wants via a toggle. That way, the user can link back to the poster's pages outside of normal post URLs provided by downloaders.
Some 3rd party applications are working on this problem. I became frustrated with hydrus's lack of meta-infromation a few years ago an over-engineered django app for it. https://github.com/bbappserver/retcon Although some people have expressed interest, there does not seem to be a strong push towards improving this scenario. But I do mainly use it for linking together several usernames and URLs to a single entity.